Goldilocks Planet Found

^^ I'm pretty sure Homo Sapiens won't be around in 5 billion years. Evolution and all that jazz.

Other thread, just for kicks.

^Well yeah, but our descendants etc.

edited 30th Sep '10 8:49:06 AM by Tzetze

Tom, Evolutionary Levels is Science Fiction. In reality, species don't evolve without selection pressure. Now, there surely may be selection pressures on humanity in the near or extended future, but those aren't inherently predictable. (Well, if climate change happens as predicted, we might soon find ourselves with a major selection pressure, but that's a digression.)

Interstellar colonization is a selection pressure, but only for that tiny fraction of the population that emigrates. By simple math, it is literally impossible to move people off Earth faster than we make more of them, unless we actually achieve ZPG or NPG on a planetary scale. The rest of us left on Earth will still have to deal with whatever's here.

The most likely case, assuming we survive as a civilized species for the next century or so, is transhumanism, where we design and direct our own development (or possibly turn it over to our AI Masters). At that point, calling it evolution is a bit of a misnomer.

edited 30th Sep '10 8:54:44 AM by Fighteer

All species are under constant natural selection pressure. Evolution takes a long time to have even noticeable changes.

The only exceptions to this is when evolution's hand is forced on a small time scale like after or during extinction level events such as the K-t event (Chicxulub impact), or Permian-Triassic extinction event.

edited 30th Sep '10 8:59:08 AM by MajorTom

I gather you are not familiar with the concept of singularity? Also, if you like, I have a Lesswrong link that explains that evolution might not work the way you seem to think it works.

edited 30th Sep '10 9:03:18 AM by RawPower

^^ The pace of human technological and cultural change is so absurdly much faster than natural selection that, barring some extinction level event, the vast majority of future human changes will be directed by ourselves (knowingly or not) rather than our environment.

edited 30th Sep '10 9:04:10 AM by Fighteer

Fighteer, it's possible that this future speciation will be driven by mechanisms other than natural selection.

I thought I was fairly clear about that. I am under the impression that Tom is not, however.

Either way it's still natural selection pressures. Only by our hands rather than the hands of Planet Earth.

Selection pressures. Calling it natural somewhat misses the point, although the word "natural" has been so abused of late that it's practically meaningless.

Ahem. No. Selection by humans is artificial. That is, kinda, you know, the opposite of natural. Just saying.

OTC, people. Much more info here: http://www.centauri-dreams.org/

The page I just linked to is a discussion of this particular planet, but there are lots of entries on other aspects of interstellar exploration. It's a huge resource, enjoy.

Isn't Tau Zero a novel that involves the end of the universe? That seems like a pretty weird name for a colonization society.

Here's the foundation's website: http://www.tauzero.aero/

The meaning of the name doesn't appear to be discussed.

Interstellar probes would also suffer because they will be subject to near-absolute zero temperatures. They need to be able to freeze and warm back up without damaging any of their components.

What is the farthest we've ever sent a probe so far?

Probably Voyager 1, at 17 billion km.

The Voyager spacecraft will be the third and fourth human spacecraft to fly beyond all the planets in our solar system. Pioneers 10 and 11 preceded Voyager in outstripping the gravitational attraction of the Sun but on February 17, 1998, Voyager 1 passed Pioneer 10 to become the most distant human-made object in space.

edited 30th Sep '10 11:30:13 AM by Tzetze

Voyager II is approximately 12 light hours from the Sun. We've still got some way to go.

Edit: Got ninja'd, and thought VII was farther for some reason.

edited 30th Sep '10 11:31:05 AM by Yej

If humans are a part of nature, then human-driven selection is natural selection. If humans aren't a part of nature, what does define "nature"?

I remember hearing about Gliese 581 before... Wasn't the presence of 581b considered a promising sign a few years back?

edited 30th Sep '10 12:05:17 PM by Tangent128

"natural selection" is usually meant to mean "selection that isn't artificial", I think, and "artificial" should be easy enough to define.

That's why I said what I said earlier: the distinction between "natural" and "artificial" is itself an artificial one and meaningless in the grand scheme of things.

Regarding the Gliese 581 system, 581d was originally thought to be potentially Earthlike but more careful study revealed that to be wrong. They also discovered several more planets; the system was originally thought to have four and now they've observed 6.

At these distances, all of this basically amounts to a ton of guesswork based on some extremely precise measurements of the motion of the objects in question. It's certainly not impossible for astronomers to be wrong about 581g, but they say they have significantly greater confidence in these figures than the ones for 581d.

And they are only starting to develop the ability to detect planets of Earthlike size; the ones here are still a fair bit larger than Earth.

Gotta say I love the terminology for exoplanets. "Hot Jupiter", "Chthonian", "puffy", and of course... SUPER-EARTH!

I'll be honest; the mere fact that we're currently able to detect something as cosmically tiny as a planet at distances of 20 light years astounds me. It's the metaphorical equivalent of finding an individual atom in a thousand-mile tall haystack.

Voyager has heater elements to ensure the delicate bits will work when asked. Power comes form an RTG - big hot lump of radioactive metal. Sometime in the next decade, the RTG will be unable to produce sufficient power to run even the heaters, so it'll be pretty much done. It's having to time-share power between instruments as it is right now.

Wonder what happened to Pioneer 10 and 11...

But hey, we found a new frontier planet? (Shiny! We found the 'Verse! Or, a bit of it, anyway.) All we need to do now is figure out a way to get there.

Generation ships, maybe?

Generation ships are the only practical means of colonizing planets that far away at STL speeds. Especially if we can't figure out constant acceleration drives.